Equalizer for rock drills



July 27 1926.

C. C. HANSEN EQUALIZER FOR ROCK DRILLS Filed Sept. 11 1925 INVENTOR. lfim ies GHanaen, 6 BY 7f a i H15 ATTO EY Patented July '27, 1926.

UNITED STATES PATENT OFFICE.

CHARLES C. HANSEN, OF EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

*EQUALIZER FOR ROCK DBILLS.

Application filed September This invention relates to rock drills, but more particularly to an air cushioned equalizer for supporting the drill steel of fluid actuated rock drills of the hammer type.

In drilling long holes for analytical, or other purposes, it is at times desirable to penetrate the rock to .a depth greatly in excess to that for ordinary mining operations. Owing to the impracticability of using a 'single steel of the desired length, the steel is usually made in sections to be connected in any convenient manner as for instance screw threads. In this way, as the steel penetrates the rock, sections may be added until the. desired depth has been drilled. Such additions, however, add greatly to the ,wei ht of the steel, which weight, during upole drilling is usually supported by the chuck parts of the drill and cause considerable wear on these parts.

It is accordingly an object of the invention to protect the chuck and associated parts against wear by preventing endthrust of .the steel against the chuck.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention consists of the combinations of elements, features of construction, and arrangement of parts having the general mode of operation substantially as hereinafter described and more particularly pointed out in'the appended claims and illustrated in the accompanying drawings, in which Figure 1 is an outline view of a rock drill mounted on a column and illustrating the manner in which the equalizer supports a heavy drill steel during inclined long hole 'drilhng, and

Figure 2 isa longitudinal view, partly in section, of the front end of a rock drill equip ed with an equalizer constructed in accor ance with the practice of the invention.

Referring to thedrawings, and more particularl to Figure 1, a drill A is shown sup? ported y a shell B havin a feed screw G which cooperates with the (Irill A and whereby the drill may be advanced towards the work as the drill steel D penetrates the rock.

.or other material to be drilled. In this instance, the shell B is secured to a suitable clamp E which holds the drill against rota- 11, 1925. Serial No. 55,677.

tive movement. The clamp E is mounted on a column F extending from the floor of a drift G to its roof and has a pair of screw acks H whereby the said column may be held firmly in position.

Ordinarily in rock drills of the hammer type, the drill steel D is supported within afront head J but in this instance, said steel 1s supported by an air cushioned equalizer K abutting the front head J. The equalizer K has a cylinder L to receive a .piston O. The piston O in this instance has a bore P to receive slidably a shank Q, of the drill steel D. The shank Q, has a reduced portion R which extends beyond the equalizer and-into the front head J.

In order to impart rotary movement to the shank Q and consequently to the drill steel D, the reduced portion R of said shank carries wings S which interlock slidably with flats or keys T formed in a chuck jaw U. The chuck aw U is rotatable within the front head J and has opposed ooves V to permit entrance of the wings S into the said chuck. The median line of the grooves V preferably intersects the median line of the keys T at right an les so that during the normal operation 0 the drill the wings S are out of line with the grooves V. In this way the shank Q is held against accidental removal from the chuck jaw U. The inner face of the chuck jaw U may be castell-ated as at W to engage similarly formed castellations on a chuck X for the purpose of preventing relative movement between said chuck aw U and the chuck X. The chuck X in this instance extends into a cylinder duced portion R of'the shank Q and also to I limit longitudinal movement of said shank .in one direction.

In order to advance the piston O .in the cylinder L, a connection 0, preferably in the form of a flexible hose, is secured to the equalizer K and communicates wlth the rearward end of the cylinder' L through a passage '1' for supplying pressure fluid to said cylinder. The connection e may-communicate either directly with a supply of pressure zfiuid or may be connected with a hose 9 which supplies pressure fluid to the drill for operating the hammer piston c. A valve 72. is attached to the connection e for controlling the admission of pressure fluid and the exhaust of pressure fluid from the cylinder L. The valve k may be of any suitable type, but is preferably of the two-way type so that the exhaust of the pressure fluid from the cylinder L may be effected through the valve to the atmosphere. I

To the end that the piston 0 maybe at all times retained within the cylinder L, a groove j is formed in the frontend of the cylinder L to receive a split expansible 7 spring ring is. The ring In is so located with respect to the piston that during the normal operation of the drill the piston 0 will not strike said ring and is employed chiefly for preventing removal of the piston when the equalizer K is detached from the drill. A shoulder 0 is in this instance formed on the shank Q to cooperate with the piston O for limiting longitudinal movement of the plston O on the shank Q in one direction. The shank Qis preferably screw threaded as at p to receive a correspondingly screw threaded end-of the drill steel D. V

In the operation of the device, let it be assumed that the drill A is positioned for up-hole drilling as indicated in Figure 1. Inthis position of the drill, the drill steel D tends to slide rearwardly so that the Wings S of the shank Q bear directly against the chuck nut d and due to the weight of the steel force the chuck X rearwardly against the cylinder Y, thus causing considerable wear on the contacting faces of these parts and also adding eatly to the resistance to rotation. To re ieve the chuck X of the weight of the drill steel 1), the valve H may be turned to a position to admit pressure fluid into the bore L rearwardly of the piston 0. Pressure fluid thus admitted into the bore L will move the piston 0 forwardly against the shoulder 0 of the shank Q and move the wings S out of contact with the chuck busing d. In this way the pressure fluid in the rearward end of the bore L will serve as a cushion against which the thrust of the drill steel may act, and since the equalizer K abuts the front end of the front head J, the weight of the drill steel D is transferred to the front end of the front head J.

The above described equalizer may be readily attached to or detached from a rock driil and, if desired, may become a permauent part of the rock drill since the reduced 7 front head, and a drill steel extending portion R of the shank Q is identical in every "respect with the ordinar drill steels of this type, so that only the s ank Q may 'be removed and ordinary drill steels may be inserted int-o the chuck. 7 Although the equalizer is described as being secured to the front head, it is to be understood that said equalizer may be abutted loosely against the 'front head in which case it will be supported entirely by the shank Q. In either case the shank Q serves to directly centralize the equalizer with respect to the front head. 7

I claim: e

1. In a fluid actuated rock drill, the combination with a front head, a chuck inthe into the chuck, of a cylinder abuttin. the front end of the front head and centra ized therewith directly by the drill steel, and a fluid actuated piston in the cylinder to support slidably support the drill steel for relieving the chuck of the weight of the drill steel.

7 3. In a fluid actuated rock'drill, the combination with a front head, a chuck rotatable in the front head, a drill steel slidable in the chuck and rotated thereby, and a collar on said drill steel, of a cylinder abutt' the front end of the front head and hel coaxial therewith directly by the drillrsteel arid a fluid actuated piston in the cylinder to slidably receive the drill steel and abut the collar to protect the chuck against the thrust of the drill steel.

4. In a fluid actuated rock drill, the combination with a front head, a chuck rotatable in the front head, a drill steel extending into the chuck and rotated thereb and a collar on said drill steel, of a cylin er secured to the front end of the front head, a fluid actuated piston in the cylinder to slidably receive t e drill steel for protectin the chuck against the weight of the steel and an expansible rin in the cylinder for retaining the piston wit in the c linder.

5. In a fluid actuated rock drill, t e oombinaticn with a front head, a chuck rotatable in the front head, a drill steel extending into the chuck and rotated thereb and a collar on' said drill steel, of a cylin er aecured to the front end of the front head, a fluid actuated iston in the c linder to receive slidably e drill steel or protect the chuck against the wei ht of the drill ste lif an expansible ring t e cylinder for re- Ill taining the piston within the cylinder, and

. rear end of the cylinder for actuating the ing into the chuck and rotated thereby, and

a collar on said drill steel, of a cylinder secured to the front end of the front head, a fluid actuated piston in the cylinder to receive slidably the drill steeLfor protecting the chuck against the weight of the drill steel, an expansiblering in the cylinder for retaining the piston within the cylinder and manually controlled means for admitting 15 pressure fluid to the rearward end of the cylinder for actuating the piston forwardly and for exhausting pressure fluid from the cylinder.

In testimony whereof I have signed this 20 specification.

' CHARLES C. HANSEN. 

